PubMed Health⌕ Search

Biomedical subjects

V Whitman

Publications and source records attributed to V Whitman.

52 records · Page 3Linked to original sources

Fatty acid oxidation by isolated perfused working hearts of aged rats.

It has been reported that mitochondria isolated from hearts of old rats have lower respiratory activity than mitochondria from young rats. In order to determine the physiological correlates of these changes, the metabolism of hearts from young and old rats has been compared in a perfused working heart preparation. The oxidation of [14C]palmitate to 14CO2, oxygen consumption, and nucleotide levels were measured under different cardiac workloads. The hearts from old animals performed less cardiac work and utilized less oxygen and palmitate in proportion to tissue mass, but the ratio of oxygen consumed to pressure developed was unaltered. There was a small but significant decrease in cardiac efficiency expressed as the ratio between the rate of oxygen consumed and ventricular pressure development. Tissue levels of total carnitine and long-chain acylcarnitine derivatives were greatly reduced in the older heart without significant change in free CoA, acetyl-CoA, or long-chain acyl-CoA. The adenine nucleotide levels were not significantly different in the two groups. The results appear consistent with the in vitro studies on isolated mitochondria.

Acetyl Coenzyme A↗

Reconstruction of the right ventricular outflow tract with a conduit in congenital heart disease.

A series of five patients with complex cyanotic congenital cardiac malformations underwent surgical reconstruction of the right ventricular outflow tract using a Dacron conduit with a porcine aortic valve. All patients survived and all have shown clinical improvement. At cardiac catheterization postoperatively, a pressure gradient of between 20 and 50 mm Hg across the conduit was found in all patients. This surgical approach to patients necessitating reconstruction of the right ventricular outflow tract is effective and appears to have the best long-term results.

Adolescent↗

Unsuspected pulmonary vascular abnormalities associated with diaphragmatic hernia.

The pulmonary vasculature of 12 newborn infants who died with unilateral diaphragmatic hernias was studied. Four developed severe ventilatory insufficiency after birth and promptly died. Their lungs were both hypoplastic and airless dur to compression by displaced abdominal viscera and mediastinal shift. Corrective surgery permitted lung expansion and adequate ventilation for one to two hours in five infants. Subsequently, ventilatory insufficiency supervened and they died. Postoperative blood gases revealed a right-to-left ductus arteriosus shunt in one infant. Ten of the infants with hernias had a significantly greater mass of muscle in pulmonary arteries than did matched controls. This may partially explain the fetal-type circulatory infants.

Ductus Arteriosus, Patent↗

Hyperreactivity to cow milk in young children with pulmonary hemosiderosis and cor pulmonale secondary to nasopharyngeal obstruction.

Six black infants and young children with high titers of milk precipitins were identified by screening the sera of 160 children with idiopathic chronic lung disease. None of the six had immunoglobulin deficiency, elevation of sweat chlorides, SS hemoglobin, or recurrent aspiration. All six children had typical manifestations of milk-induced pulmonary hemosiderosis: recurrent pulmonary infiltrates (6/6), hemosiderin-laden pulmonary macrophages (5/6), intermittent wheezing (5/6), eosinophilia (4/6), anemia (4/6), iron deficiency (4/4), failure to thrive (4/6), and elevated levels of serum IgE (4/4). Three children also had chronic rhinitis and eventually developed large adenoids, hypercapnia and acidosis during sleep, and right heart failure. Elimination of cow milk from the diet, symptomatic therapy, and adenoidectomy when indicated resulted in improvement of all six patients. Pulmonary hemosiderosis and some cases of upper airway obstruction with pulmonary hypertension appear to be two stages, early and delayed, of the same immunophysiologic process. Early dietary intervention may prevent the cardiovascular complications of this process.

Black or African American↗

Studies on cor pulmonale in cystic fibrosis: I. Effects of diuresis.

The effects of acute diuresis in patients with cor pulmonale secondary to cystic fibrosis were studied. Both hemodynamic parameters and arterial blood gas changes were investigated. The major effect noted was a significant reduction of systemic venous pressure. Pulmonary artery and pulmonary artery wedge pressure either remained constant or declined slightly. No consistent changes were noted in cardiac output or arterial blood gases. Acute diuresis of moderate degree appears to be a safe and effective manner in which to treat the systemic venous congestion of cor pulmonale in this situation.

Acid-Base Equilibrium↗

Indomethacin disposition and indomethacin-induced platelet dysfunction in premature infants.

Indomethacin failed to produce permanent ductal closure in any of four premature infants with patent ductus arteriosus to whom the drug was given. Indomethacin half-lives measured in two premature infants were 21 and 24 hours, respectively, much longer than in full-term newborns or adults. Platelet function, as measured by platelet aggregation, was grossly abnormal for two to four days after indomethacin administration, normal values returning only by the ninth and tenth days. Gastrointestinal bleeding and transient renal dysfunction occurred in one infant. Measurement of plasma indomethacin concentrations in sick, low-birthweight infants could help guide indomethacin dose and dosage interval, prevent drug accumulation, and reduce toxicity. Further studies of potential toxicity seem to be indicated before instituting widespread indomethacin administration for ductal closure in premature infants.

Blood Platelet Disorders↗

Factors accounting for growth and atrophy of the heart.

Growth of the rat heart was induced by intrathoracic aortic banding, while atrophy followed hypophysectomy. During the early phase of hypertrophy, RNA concentration increased markedly. During the period of atrophy, RNA concentration was reduced. These changes in RNA concentration seemed to account for either the increased or the decreased rates of protein synthesis that was observed during hypertrophy or atrophy, respectively. Rates of protein degradation were unaffected during changes in heart size. These findings suggest that alterations in synthesis, processing, or degradation of RNA play a key role in modification of heart size.

Aging↗